Small-size laser light source module and preparation method thereof

Abstract

The invention provides a small-size laser light source module which comprises a tube shell and two laser chips, the tube shell is composed of a heat conduction base, a kovar transition ring and a ceramic frame and used for leading out heat of the laser chips and leading out electrodes of the laser chips; wherein the ceramic frame is arranged on the outer side of the heat conduction base in a sleeving mode, the kovar transition ring is welded between the heat conduction base and the ceramic frame, the heat conduction base comprises a flat plate playing a sealing role and an inclined face for supporting a chip, and the inclined face is in an isosceles trapezoid shape; according to the laser light source module, the heat conduction path of the laser chip and the heat transfer path of the wavelength conversion sheet are separately arranged and do not influence each other, so that the service life of the laser light source module is longer. The short excitation optical path is adopted, the brightness of white light output by the laser light source module is higher, and the overall size is smaller. According to the laser light source module, no optical auxiliary element is adopted, so that the assembly efficiency is high, and the yield is high.

Description

Technical Field

[0001] The invention relates to a laser light source module, in particular to a small-volume laser light source module, and belongs to the technical field of light source modules. Background Art

[0002] A laser light source module is a small module that integrates a laser light source (usually a laser diode) with related optical components. This module usually includes a laser generator, an optical system, a thermal management system, a control circuit, and a fiber coupler. In different applications, such as communications, medical treatment, industrial processing, and entertainment, the composition of a laser light source module may vary, but the core purpose is to convert the high brightness and monochromaticity of a laser light source into an output form suitable for a specific application.

[0003] Existing laser light source modules such as Fig.11 As shown, the laser chip is first packaged into a small tube shell, and the light is deflected by a reflector before being lasered onto the wavelength conversion plate. The reflector plays the role of deflection direction. The optical path of the two beams of light to the wavelength conversion device is equal, and the light spots of the two excitation lasers partially or completely overlap at the wavelength conversion plate.

[0004] However, in actual operation, the reflector and the two chips need to be aligned, which is difficult to operate and the process is complicated. In addition, the excitation light is input perpendicular to the wavelength conversion plate, and the optical axis of the unabsorbed excitation light is also output perpendicular to the wavelength conversion plate, which is not conducive to the subsequent light mixing.

[0005] To this end, a small-volume laser light source module and a preparation method thereof are proposed. Summary of the invention

[0006] In view of this, the present invention provides a small-volume laser light source module and a preparation method thereof to solve or alleviate the technical problems existing in the prior art, and at least provide a beneficial choice.

[0007] The technical solution of the embodiment of the present invention is implemented as follows: a small-volume laser light source module includes a tube shell and two laser chips, wherein the tube shell is composed of a heat-conducting base, a Kovar transition ring and a ceramic frame, and is used to conduct heat from the laser chip and lead out the electrode of the laser chip;

[0008] The ceramic frame is sleeved on the outer side of the thermally conductive base, the Kovar transition ring is welded between the thermally conductive base and the ceramic frame, and the thermally conductive base includes a flat plate for sealing and an inclined surface for supporting the chip, and the inclined surface is an isosceles trapezoid;

[0009] The oblique surface of the thermal conductive base is symmetrically fixedly connected with two transition heat sinks, and the two laser chips are respectively fixed on the two transition heat sinks;

[0010] The ceramic frame is provided with an inward protrusion inside for bonding and leading out the electrode of the laser chip, the bottom of the ceramic frame is symmetrically provided with four pads, and the ceramic frame is provided with a metallized wire inside for leading out the electrode to the pad;

[0011] A heat conducting plate is welded to the upper surface of the ceramic frame, and a wavelength conversion sheet is welded to the inner side wall of the heat conducting plate.

[0012] Further preferably, the angle between the plate and the inclined surface of the thermal conductive base is θ, and the value of θ ranges from 15° to 65°; the length of the inclined surface is L, and the length of the transition heat sink is L 过渡热沉 ;

[0013] Where L = L 过渡热沉 +0.1-0.4(mm);

[0014] In the vertical direction, the height contributed by the laser chip and the transition heat sink is H3;

[0015] That is, H3 = H1 + H2 = L*sinθ + H*cosθ;

[0016] Wherein, L represents the length of the transition heat sink, H1 represents the height of the transition heat sink, and H2 represents the height of the laser chip.

[0017] Further preferably, the wavelength conversion sheet includes an incident surface S1 and an exit surface S2;

[0018] The incident surface S1 is coated with a two-color film for enhancing the transmittance of the wavelength of the excitation light.

[0019] Further preferably, the angle between the light emitting surface of the laser chip and the light incident surface of the wavelength conversion plate is 25-65°.

[0020] Further preferably, the Kovar transition ring has a thickness of 0.1-0.5 mm and is used to transition the thermal expansion coefficient between the heat-conducting base and the ceramic frame.

[0021] Further preferably, the thermally conductive base is made of oxygen-free copper material, and the ceramic frame is made of alumina ceramic.

[0022] Further preferably, a method for preparing a small-volume laser light source module comprises the following steps:

[0023] The first step is to sinter the ceramic frame under high temperature conditions;

[0024] The second step is to use silver-copper solder to weld the thermal conductive base, the Kovar transition ring and the ceramic frame to obtain a tube shell, and then plate nickel and gold inside the tube shell to form a metallized area;

[0025] The third step is to use a die bonding machine to sinter the laser chip on the transition heat sink to obtain component one;

[0026] Step 4: Place the component on the inclined surface of the heat-conducting base in the tube shell and sinter and solidify it;

[0027] Step 5: Using a gold wire bonding machine, lead the electrode leads on the laser chip to the metallized area in the tube shell to obtain component 2;

[0028] Step 6: Use sintered silver solder to sinter and fix the wavelength conversion sheet in the groove of the heat conducting plate to obtain component three;

[0029] The seventh step is to weld and seal component three and component two to obtain a laser light source module.

[0030] In the first step, the temperature under high temperature conditions is 1200-1600°C.

[0031] In the second step, the melting point of the silver-copper solder is 780° C., and the solder contains 72% silver and 28% copper.

[0032] The flat plate for sealing and the inclined surface for supporting the chip in the heat-conducting base are formed by one-piece processing or by split-piece production and then welded.

[0033] The embodiment of the present invention has the following advantages due to the adoption of the above technical solution:

[0034] 1. The present invention provides a longer service life of the laser light source module by separating the heat conduction path of the laser chip from the heat conduction path of the wavelength conversion sheet without affecting each other.

[0035] 2. The present invention adopts a shorter excitation optical path, so that the white light output by the laser light source module is brighter and the overall volume is smaller.

[0036] 3. The laser light source module of the present invention does not use any optical auxiliary components, so that its assembly efficiency is high and the yield rate is high.

[0037] The above summary is for illustrative purposes only and is not limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a structural diagram of the present invention;

[0040] Figure 2 An exploded view of the tube shell of the present invention;

[0041] Figure 3 It is a schematic diagram of the side structure of the heat-conducting base of the present invention;

[0042] Figure 4 It is a schematic diagram of the top view of the heat conducting base of the present invention;

[0043] Figure 5 It is a structural schematic diagram of the inclination angle of the inclined surface of the heat conducting base of the present invention;

[0044] Figure 6 A schematic diagram of energy superposition on the wavelength conversion sheet of the present invention;

[0045] Figure 7 It is a schematic diagram of the structure of the kovable transition ring of the present invention;

[0046] Figure 8 Schematic diagrams of the ceramic frame of the present invention in top, side and bottom views;

[0047] Fig. 9 It is a schematic diagram of the structure of the wavelength conversion sheet and the heat conducting plate of the present invention;

[0048] Fig.10 is an isometric view of the light source module of the present invention;

[0049] Fig.11 It is a structural schematic diagram of the prior art solution.

[0050] Figure numerals: 1. thermal conductive base; 2. Kovar transition ring; 3. ceramic frame; 4. laser chip; 5. transition heat sink; 6. wavelength conversion sheet; 7. thermal conductive plate. DETAILED DESCRIPTION

[0051] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0052] It should be noted that the terms "first", "second", "symmetrical", "array", etc. are only used to distinguish between description and position description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the definition of "first", "symmetrical", etc. can explicitly or implicitly include one or more of these features; similarly, when the number of certain features is not limited in the form of words such as "two" or "three", it should be noted that this feature also explicitly or implicitly includes one or more feature quantities.

[0053] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0054] like Figure 1-Figure 10 As shown, the embodiment of the present invention provides a small-volume laser light source module, including a tube shell and two laser chips 4. The tube shell is composed of a heat-conducting base 1, a Kovar transition ring 2 and a ceramic frame 3. The structure of the tube shell is as follows: Figure 2 As shown, the ceramic frame 3 is made by high temperature process and is used to conduct heat of the laser chip 4 and lead out the electrodes of the laser chip 4;

[0055] The ceramic frame 3 is sleeved on the outer side of the thermal conductive base 1, the Kovar transition ring 2 is welded between the thermal conductive base 1 and the ceramic frame 3, and the thermal conductive base 1 includes a flat plate for sealing and an inclined surface for supporting the chip, and the inclined surface is an isosceles trapezoid;

[0056] The inclined surface of the heat conducting base 1 is symmetrically fixedly connected with two transition heat sinks 5, and the two laser chips 4 are respectively fixed on the two transition heat sinks 5;

[0057] The ceramic frame 3 is provided with an inward protrusion inside for bonding and leading out the electrode of the laser chip 4. The bottom of the ceramic frame 3 is symmetrically provided with four pads. The ceramic frame 3 is provided with a metallized wire inside for leading out the electrode to the pad. Figure 8 As shown, the height of the overall ceramic frame 3 is about 1.6 mm;

[0058] A heat conducting plate 7 is welded to the upper surface of the ceramic frame 3, and a wavelength conversion sheet 6 is welded to the inner wall of the heat conducting plate 7; the wavelength conversion device is characterized by absorbing laser light with a shorter wavelength and emitting fluorescence with a longer wavelength; generally, there are two types of wavelength conversion devices, emitting yellow-green light of 500-560nm and red light of 630-670nm; the wavelength conversion device needs to conduct the laser energy that cannot be converted, so it is necessary to properly dissipate heat for the wavelength conversion sheet. The wavelength conversion and heat dissipation device designed by the present invention is as follows Fig. 9 As shown, the heat conducting plate 7 is used to conduct away the unconverted heat on the wavelength conversion plate 6 and seal the tube shell to prevent dust, water vapor, oxygen and other pollutants from damaging the laser chip 4.

[0059] In one embodiment, Figure 3 and Figure 4 As shown, the angle between the plate and the inclined surface of the thermal conductive base 1 is θ, and the value of θ ranges from 15 to 65°; the length of the inclined surface is L, the length of the upper bottom is W, and the length of the transition heat sink 5 is L 过渡热沉 ;

[0060] Where L = L 过渡热沉 +0.1-0.4(mm);

[0061] like Figure 5 As shown, the thermal conductive base 1 is provided with an inclined plane with an angle of θ, and the value of θ is in the range of 15°-65°. The inclined plane is symmetrically arranged. The length L of the inclined plane is generally the length of the transition heat sink + 0.1-0.4 mm.

[0062] When a three-watt laser chip is packaged, its length is generally 1.2mm, so the length of the transition heat sink is generally 1.5-1.6mm;

[0063] In the vertical direction, the height contributed by the laser chip 4 and the transition heat sink 5 is H3;

[0064] That is, H3 = H1 + H2 = L*sinθ + H*cosθ;

[0065] Wherein, L represents the length of the transition heat sink 5 , H1 represents the height of the transition heat sink 5 , and H2 represents the height of the laser chip 4 .

[0066] That is, in the extreme case, when the distance between the lower edge of the wavelength conversion sheet 6 and the laser chip 4 is zero, the thickness of the module can be the thinnest. Considering the feasibility of the actual process, the distance between the two is generally controlled to be 0.2-0.5 mm.

[0067] After setting the distance between the laser chip 4 and the wavelength conversion plate 6, the size of the light spot in the fast axis direction can be calculated according to the following formula:

[0068] d1=d*tg(90-θ+φ1)-d*tg(90-θ-φ2);

[0069] When the angle θ is larger, the height of the overall module will be higher. At 90°, the height of the module reaches the highest, forming a vertically incident wavelength conversion sheet 6. At this time, the intersection of the two beams of light is completely determined by the value of w.

[0070] In order to obtain a thinner device and a smaller excitation light area, it is necessary to select a better θ value according to the thickness of the transition heat sink 5, the energy density that the wavelength conversion plate 6 can withstand, and the vertical divergence angle of the laser.

[0071] In one embodiment, the wavelength conversion sheet 6 includes an incident surface S1 and an exit surface S2;

[0072] Among them, the incident surface S1 is coated with a two-color film for enhancing the wavelength transmittance of the excitation light; the incident surface S1 of the wavelength conversion plate 6 is coated with a two-color film, that is, the wavelength transmittance of the excitation light is enhanced, and the wavelength emitted by the excitation is highly reflected on the S1 surface and emitted from the other surface S2. Fig. 9 shown.

[0073] In one embodiment, the angle between the light emitting surface of the laser chip 4 and the light incident surface of the wavelength conversion plate 6 is 25-65°;

[0074] According to the maximum energy density that the wavelength conversion plate 6 can withstand, the bottom angle of the trapezoid can be set between 15° and 65°. According to the light-emitting characteristics of semiconductor lasers, the smaller the angle, the lower the energy density of the excitation light, and the lower the energy density irradiated on the wavelength conversion plate 6. Vice versa. The energy superposition of two chips on the wavelength conversion plate is shown in the figure below: Figure 6 As shown, since the two chips are symmetrically arranged, when the distance between the chip and the wavelength conversion plate 6 is determined (under the premise that the angle θ is determined), the size of the light spot is determined. The size of the overlapping area of ​​the two light spots can be determined according to the value of w. Generally, the value of w is 0.2-2mm. In this example, we take w = 0.7mm. θ = 35.

[0075] In one embodiment, Figure 7 As shown, the thickness of the Kovar transition ring 2 is 0.1-0.5 mm, and is used to transition the thermal expansion coefficient between the heat conductive base 1 and the ceramic frame 3 .

[0076] The Kovar transition ring 2 is placed between the heat-conducting base 1 and the ceramic frame 3 to transition the thermal expansion coefficients of the two, thereby avoiding deformation after welding due to the huge difference in expansion coefficients between the heat-conducting base 1 and the ceramic frame 3.

[0077] In one embodiment, the material of the thermal conductive base 1 is oxygen-free copper material, and the material of the ceramic frame 3 is alumina ceramic;

[0078] The thermal conductive base 1 is made of oxygen-free copper material. The thickness of the plate can be set as needed, and the size can also be set according to the installation position. In this example, the plate is 0.8 mm thick, 4.5 mm wide, and 5.3 mm long.

[0079] Embodiment 2

[0080] Based on the first embodiment, the present invention also provides a method for preparing a small-volume laser light source module, comprising the following steps:

[0081] The first step is to sinter the ceramic frame 3 under high temperature conditions, wherein the temperature under high temperature conditions is 1200-1600° C.;

[0082] In the second step, the heat-conducting base 1, the Kovar transition ring 2 and the ceramic frame 3 are welded with silver-copper solder to obtain a tube shell, and nickel-gold is plated inside the tube shell to form a metallized area. The melting point of the silver-copper solder is 780°C, and the solder contains 72% silver and 28% copper. The flat plate that acts as a seal and the inclined surface that supports the chip in the heat-conducting base 1 are formed by one-piece processing;

[0083] The third step is to sinter the laser chip 4 on the transition heat sink 5 by using a die bonding machine to obtain component 1;

[0084] Step 4: Place component 1 on the inclined surface of the heat-conducting base 1 in the tube shell and sinter and solidify it;

[0085] Step 5: Using a gold wire bonding machine, lead the electrode leads on the laser chip 4 to the metallized area in the tube shell to obtain component 2;

[0086] Step 6: Use sintered silver solder to sinter and fix the wavelength conversion sheet 6 in the groove of the heat conducting plate 7 to obtain component three;

[0087] Step 7: Weld and seal component 3 and component 2 to obtain a laser light source module. Fig.10 shown.

[0088] Embodiment 3

[0089] Based on the first embodiment, the present invention also provides a method for preparing a small-volume laser light source module, comprising the following steps:

[0090] The first step is to sinter the ceramic frame 3 under high temperature conditions, wherein the temperature under high temperature conditions is 1200-1600° C.;

[0091] In the second step, the heat-conducting base 1, the Kovar transition ring 2 and the ceramic frame 3 are welded with silver-copper solder to obtain a tube shell, and nickel-gold is plated inside the tube shell to form a metallized area. The melting point of the silver-copper solder is 780°C, and the solder contains 72% silver and 28% copper. The flat plate that serves as a seal and the inclined surface that supports the chip in the heat-conducting base 1 are made in a split type and then welded into shape.

[0092] The third step is to sinter the laser chip 4 on the transition heat sink 5 by using a die bonding machine to obtain component 1;

[0093] Step 4: Place component 1 on the inclined surface of the heat-conducting base 1 in the tube shell and sinter and solidify it;

[0094] Step 5: Using a gold wire bonding machine, lead the electrode leads on the laser chip 4 to the metallized area in the tube shell to obtain component 2;

[0095] Step 6: Use sintered silver solder to sinter and fix the wavelength conversion sheet 6 in the groove of the heat conducting plate 7 to obtain component three;

[0096] The seventh step is to weld and seal component three and component two to obtain a laser light source module.

[0097] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A small-volume laser light source module, comprising a tube shell and two laser chips (4), characterized in that: The tube shell is composed of a heat-conducting base (1), a Kovar transition ring (2) and a ceramic frame (3), and is used to conduct heat from the laser chip (4) and to lead out the electrodes of the laser chip (4); The ceramic frame (3) is sleeved on the outer side of the thermally conductive base (1), the Kovar transition ring (2) is welded between the thermally conductive base (1) and the ceramic frame (3), and the thermally conductive base (1) comprises a flat plate having a sealing function and an inclined surface for supporting the chip, and the inclined surface is in an isosceles trapezoidal shape; Two transition heat sinks (5) are symmetrically and fixedly connected to the oblique surface of the thermal conductive base (1), and the two laser chips (4) are respectively fixed on the two transition heat sinks (5); An inward protrusion is provided inside the ceramic frame (3) for bonding and leading out electrodes of the laser chip (4); four pads are symmetrically provided at the bottom of the ceramic frame (3); and a metallized wire is provided inside the ceramic frame (3) for leading out the electrodes to the pads; A heat conducting plate (7) is welded to the upper surface of the ceramic frame (3), and a wavelength conversion plate (6) is welded to the inner side wall of the heat conducting plate (7).

2. The small-volume laser light source module and the method for preparing the same according to claim 1, characterized in that: The angle between the plate and the inclined surface of the thermal conductive base (1) is θ, and the value of θ ranges from 15 to 65°; the length of the inclined surface is L, and the length of the transition heat sink (5) is L 过渡热沉 ; Where L = L 过渡热沉 +0.1-0.4(mm); In the vertical direction, the height contributed by the laser chip (4) and the transition heat sink (5) is H3; That is, H3 = H1 + H2 = L*sinθ + H*cosθ; Wherein, L represents the length of the transition heat sink (5), H1 represents the height of the transition heat sink (5), and H2 represents the height of the laser chip (4).

3. The small-volume laser light source module and the method for preparing the same according to claim 1, characterized in that: The wavelength conversion plate (6) comprises an incident surface S1 and an exit surface S2; The incident surface S1 is coated with a two-color film for enhancing the transmittance of the wavelength of the excitation light.

4. The small-volume laser light source module and the method for preparing the same according to claim 3, characterized in that: The angle between the light emitting surface of the laser chip (4) and the light incident surface of the wavelength conversion plate (6) is 25-65°.

5. The small-volume laser light source module and the method for preparing the same according to claim 1, characterized in that: The Kovar transition ring (2) has a thickness of 0.1-0.5 mm and is used to transition the thermal expansion coefficient between the heat-conducting base (1) and the ceramic frame (3).

6. The small-volume laser light source module and the method for preparing the same according to claim 1, characterized in that: The material of the thermally conductive base (1) is oxygen-free copper material, and the material of the ceramic frame (3) is alumina ceramic.

7. A method for preparing a small-volume laser light source module according to any one of claims 1 to 6, characterized in that: The following steps are involved: The first step is to sinter the ceramic frame (3) under high temperature conditions; The second step is to use silver-copper solder to weld the heat-conducting base (1), the Kovar transition ring (2) and the ceramic frame (3) to obtain a tube shell, and to plate nickel and gold inside the tube shell to form a metallized area; The third step is to use a die bonding machine to sinter the laser chip (4) onto the transition heat sink (5) to obtain component 1; Step 4: Place component 1 on the inclined surface of the heat-conducting base (1) in the tube shell and sinter and solidify it; Step 5: Using a gold wire bonding machine, lead the electrode leads on the laser chip (4) to the metallized area in the tube shell to obtain component 2; Step 6: Using sintered silver solder to sinter and fix the wavelength conversion sheet (6) in the groove of the heat conducting plate (7) to obtain component three; The seventh step is to weld and seal component three and component two to obtain a laser light source module.

8. The method for preparing a small-volume laser light source module according to claim 7, characterized in that: In the first step, the temperature under high temperature conditions is 1200-1600°C.

9. The method for preparing a small-volume laser light source module according to claim 7, characterized in that: In the second step, the melting point of the silver-copper solder is 780° C., and the solder contains 72% silver and 28% copper.

10. The method for preparing a small-volume laser light source module according to claim 7, characterized in that: In the second step, the flat plate that performs a sealing function and the inclined surface portion that supports the chip in the heat-conducting base (1) are formed by one-piece processing or by separate production, and then welded into shape.

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